JPS62201289A - Light information recording medium - Google Patents

Abstract

PURPOSE:To obtain a light information recording medium having a high reflection factor and recording sensitivity where an optical signal can be written and reproduced stably with high stability against the sunshine or the humidity during reproduction without causing contamination, by providing a recording layer containing a specific organic pigment. CONSTITUTION:It is a light information recording medium having a recording layer containing an organic pigment shown by a general formula. In the organic pigment, a functional group of the carbon number of 2-20 having an unsaturated bond is introduced as Y into an indole so as to compensate the solubility, the filming performance onto a substrate and the moistening performance against the substrate, thus improving the contact tight strength against the recording layer. A high density recording layer containing the organic pigment can also be achieved. When (Z)m is introduced to a benzene ring constituting an indole, the spectral characteristic, the light withstanding performance and the chemical stability can be improved. Consequently, when a recording layer containing such an organic pigment is formed, a light information recording medium where the noise component in a reproduced signal waveform due to a defective film is reduced while the environmental withstandability such as the moisture withstandability and the reproduction deteriorating performance are improved considerably can be obtained.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to writing using a laser, particularly a semiconductor laser,
The present invention relates to an optical memory medium on which playback and recording are performed.

[Prior art and problems]

Generally, optical disks can store high-density information using optically detectable small (eg, about 1 ρ) bits formed in a thin film recording layer on a substrate in the form of spiral or circular tracks. To write information on such a disk, a focused laser beam is scanned onto the surface of the laser-sensitive layer, a bit is formed only on the surface irradiated with the laser beam, and the bit is shaped like a spiral or circular track. form in form. This sensitive layer can absorb laser energy to form an optically detectable bit. For example, in the heat mode recording method, the recording layer absorbs laser energy and the irradiated area is locally heated, causing physical changes such as melting, evaporation, or aggregation, resulting in optical differences (e.g. reflectance, etc.) between the recording layer and the non-irradiated area. absorption rate, etc.) and reading it.

As such optical recording media, inorganic materials such as metal thin films such as aluminum vapor-deposited films, bismuth thin films, tellurium-based thin films, and chalcogenide-based amorphous glass films have been proposed.

These have the advantage that thin films can be obtained by vapor deposition, sputtering, etc., and semiconductor lasers can be used because they absorb light even in the near-infrared region, but on the other hand, they have high reflectance, high thermal conductivity, and high specific heat. There are drawbacks such as. In particular, if the reflectance is high, the energy of the laser beam cannot be used effectively, so the optical energy required for recording is large, and a high-output laser light source is required. the result,
The drawback is that the recording device is large and expensive. Furthermore, thin films of tellurium, bismuth, selenium, etc. have the disadvantage of being toxic. For these reasons, in recent years, optical memory media using a thin dye film as a recording layer have been developed because it is possible to select the absorption property, has a high absorption rate, low heat conduction, good productivity, and low toxicity. Research proposals have been made. Typical dyes include cyanine dyes (JP 58-112790), anthraquinone dyes (JP 58-224448), naphthoquinone dyes (JP 58-224793), and phthalocyanine dyes (JP 58-224793). -48396), etc., and is an optical recording medium in which a compound consisting of these alone or in combination with a self-oxidizing resin is formed on a substrate by spinner coating, dipping, plasma, vacuum evaporation, or the like. This dye thin film system has the above-mentioned advantages; in particular, cyanine dyes are structurally capable of having an absorption wavelength in the near infrared, and also have advantages such as low solubility in solvents and low melting point. Much consideration has been made. On the other hand, it has traditionally been said that there are problems with light deterioration, instability against heat, humidity deterioration, etc., long-term storage stability, playback stability (stability against readout light), etc. A number of improvement proposals have been proposed. Specifically, providing a protective film on the recording layer (JP-A-55-22961.57-66541);
Mixing a substance that prevents fading due to oxygen
55795) and the addition of a metal complex having light absorption in a long wavelength region (Japanese Patent Laid-Open No. 59-215892). However, these proposals do not sufficiently solve the problem, and furthermore, problems arise in that the film formability, reflectance, and absorption rate are reduced by the additives.

For these reasons, a coating type recording medium using a cyanine dye represented by the following general formula is attracting attention in terms of recording density and reflectivity.

[However, in the formula, A is O, S, Se, C,

However, even with the cyanine dye represented by the above general formula, there is an essential problem that film forming properties and heat and light stability are lacking. Regarding film formability, the number of methine chains (n)
It is known that solvent solubility decreases due to an increase in , and that solubility changes depending on the type of heterocycle at both ends and the type of substituent. Regarding thermophotostability, it is known that as the number of methine chains increases, it becomes more unstable to heat and light, and oxidative degradation is more likely to occur, and that the stability to heat and light differs depending on the type of heterocycle. It is being

The present invention was developed in view of the above circumstances, and has high reflectance and high recording sensitivity, enables stable writing and reproduction of optical signals, and is capable of handling light and sunlight during reproduction.
The purpose is to provide a pollution-free original information recording medium that is highly stable against humidity.

[Means and effects for solving the problems] The present invention is an optical information recording medium characterized by having a recording layer containing an organic dye represented by the following general formula.

However, R4 in the formula is an alkyl group having 1 to 6 carbon atoms, an allyl group, an aralkyl group, a phenyl group, and L is (CH=CH4
nCHCn = integer from 1 to 4], CH=C)I-CH
=CH-C=CH-CH=CH-CH [W: indicates a monovalent group] (poly)methine chain group, X is 9-chlorate, fluorochlorate, iodide, chloride, bromide, The ion selected from p-toluenesulfonate, Y is 2 to 2 carbon atoms forming an unsaturated bond.
The functional group o, 2 is a hydrogen atom, a halogen atom, an alkyl group having 1 to 18 carbon atoms, an allyl group, a nitro group, a human (R2:
20 alkyl group, R3: alkyl group having 1 to 18 carbon atoms) or a benzene ring added to the benzene ring constituting indole, m is an integer of 1 to 4.

The organic dye used in the present invention is represented by L between two indoles (CH=CH+nCH).

By introducing a chain fund, the spectral characteristics can be improved. The above W represents a monovalent group. Examples of this monovalent group include CI, halogen atoms such as Br, methyl, 4% 0l
-C5 alkyl group, alkoxy group such as methoxy group, unsubstituted or t-substituted aryl group, alkylamino group, alkylamino or arylamino group, dimethylamino group, diphenylamino group, methylphenylamino group, morpholino group, imidazo Substituted amino groups such as lysine groups, alkylcarbonyloxy, cyan groups, nitro groups, hydroxyl groups, carboxyl groups, and h -C-0-R4 (R4 is C4 to C5
(representing an alkyl group, phenyl group or substituted phenyl group), and the like. In general, halodane atoms such as C1 and Br, alkyl groups of 01 to 5, methoxy groups, or di-substituted amino groups such as dialkylamino groups and diphenylamino groups are generally used, depending on the properties and ease of production. Often used.

In the organic dye used in the present invention, a functional group having 2 to 2 carbon atoms and having an unsaturated bond is introduced into indole as Y to improve solubility, film formability on the substrate, and wettability with the substrate. I can do it. In particular, improving the wettability with the substrate increases the adhesion strength of the recording layer. Further, by introducing Y, it is possible to increase the density of the recording layer containing the organic dye. Examples of such a functional group having 2 to 20 carbon atoms having an unsaturated bond include an unsubstituted or substituted allyl group, a vinyl group,
Examples include allylidene group, allyloxy group, crotonoyl group, styryl group, vinylidene group, vinylene group, diene group, methylidine group, acryloyl group, methacryloyl group, impropenyl group, ethynyl group, and butenyl group. When such a functional group has a large number of carbon atoms, the film forming property becomes good, but there is a possibility that the moisture resistance decreases, so it is preferable that the functional group has a straight chain carbon number of 2 to 9.

Furthermore, the organic dye used in the present invention has improved spectral characteristics, light resistance, and chemical stability by introducing (Z)m (m = an integer of 1 to 4) into the benzene ring constituting the indole. These 2 are as described above, but when a linear carbon number-rich material is introduced, solubility and film-forming properties are improved.

However, since the Y introduced into the indole described above improves the solubility of the dye and the film-forming properties, it is also possible to introduce as the above-mentioned 2 something that does not contribute to the solubility, such as a benzene ring. In any case, when introducing 2, the above Y
It is desirable to make a selection that takes into consideration the following. In addition, when introducing 2 into the benzene ring that constitutes indole,
Although any of the 4th, 5th, and 6th positions are possible, the 5th position is particularly preferred as it is the easiest to substitute.

As described above, the organic dye of the present invention into which Y, Z, etc. are introduced is disclosed in JP-A-58-56239. Japanese Patent Publication No. 58-112790
, Japanese Patent Publication No. 58-219091. Japanese Patent Publication No. 58-1945
95. JP-A-59-150795, JP-A-59-124
It has superior spectral properties (high reflectivity, etc.) compared to the dyes disclosed in No. 045, etc., and has excellent chemical stability, light resistance, solvent solubility,
Excellent film forming properties and wettability with substrates. Therefore, by forming a recording layer containing such an organic dye, it is possible to obtain an optical information recording medium in which the noise component of the reproduced signal waveform due to film formation defects is reduced, and the environmental resistance such as moisture resistance and reproduction deterioration characteristics are significantly improved. be able to.

Specific examples of the dye represented by the above general formula include:
Examples include those shown in structural formulas (1) to (g) below.

(2)
So i-, d q Q
Go
d1/- ro 3 ε 3 do:
6saξ) d 8 8
Tsukugo
ζgoego, ■? ■25 d
and g ■ S R 8 Inquiry 8 Kugo 2 8 g The recording layer containing the dye represented by the above general formula is prepared by mixing the dye with ethyl acetate, toluene, acetone, methyl ethyl ketone, methyl isobutyl ketone, methine chloride/chloroform. It can be obtained by dissolving it in a solvent such as dichloroethane, tetrahydrofuran, or alcohol and forming a thin film on a substrate by a spinner method, dipping method, doctor blade method, roll coater method, or the like. The thinner the thickness of this recording layer, the higher the recording sensitivity, but since the reflectance depends on the film thickness, it is appropriate to set the thickness in the range of 10 nm to 1000 nm, preferably 30 nm to 500 nm. be. Further, as the substrate, plates and films of plastics such as polyester, acrylic resin, polycarnate resin, polyolefin resin, phenol resin, epoxy resin, polyamide resin, polyimide resin, glass, metals, etc. can be used.

The recording layer can be formed into a film by the method described above.9 It is also possible to form a film by adding 1 to 40% by weight, preferably 3 to 20% by weight, of a binder resin to the dye. Heat resistance and moisture resistance can be improved. Examples of the binder resin used here include acrylic, ester, nitro-heptylulose, ethylene, Probile:/, and carol. Examples include resins such as (N), ethylene terephthalate, urethane, epoxy, butyral, vinyl chloride, vinyl acetate, and styrene, and composites of copolymers of these may also be used.

In addition, by mixing other dyes in place of the binder resin or creating a multilayer structure in which dye layers are stacked, film formability, heat resistance, moisture resistance, and light resistance can be improved, resulting in higher density. Therefore, it is possible to obtain an optical information recording medium with high sensitivity and excellent durability without reproduction deterioration. In this case, it is also possible to layer other dyes to improve heat resistance, moisture resistance, and light resistance. Examples of dyes used here include cyanine dyes, merocyanine dyes, anthraquinone dyes, triphenylmethane dyes, xanthine dyes,
Examples include phthalocyanine dyes.

Furthermore, for example, an amine compound represented by the following general formula (0) or a dithiolate metal complex represented by the following general formula (C) is added to prevent deterioration of the optical properties of the recording layer due to light, oxygen, and moisture. It is also possible to do so.

However, Rle R2e R4t R5 in the formula has 1 carbon number
-6 alkyl group, R3 is 10-C"R, -0-R.

Here, R represents an alkyl group having 1 to 6 carbon atoms.

...(B) However, in the formula, R is a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, X is an anion such as perchlorate ion, fluoroborate ion, hexafluoroate ion, etc., and m is 0 or an integer of 1, 2, A is the above m=o, 1 is, for example, a commercially available IR
There are Q-002, IRQ-003 (all brand names manufactured by Nippon Kayaku ■), etc.

However, R1-R4 in the formula is an alkyl group or a phenyl group,
x, y are hydrogen, alkyl group, halogen group, M is Ni p
This indicates metals such as Co and Fe + Cr. Such a metal complex may have a pA of 1001 to 100, for example.
6 (all names of parts manufactured by Mitsui Toatsu Fine Co., Ltd.), Ni
-bis(0-xylene-4,5diol)tetra(t-
butyl) ammonium salt etc.

In addition to the recording layer containing the dye of the above general formula, an intermediate layer and a protective layer may be provided as necessary. The intermediate layer is provided for the purpose of improving adhesion and protecting from oxygen and moisture, and is mainly formed from a resin or an inorganic compound. As the resin, for example, single or copolymers of vinyl chloride, vinyl acetate, acrylic, ester, nitrocellulose, carbanate, epoxy, ethylene, propylene, butyral, etc. can be used, and if necessary, antioxidants,
It is possible to contain an ultraviolet light absorber, a leveling agent, a water repellent, etc. These films are formed by a spinner method, a dipping method, or a doctor blade method. Examples of inorganic compounds include 8102, 810, At20
5+5n02p MgF2 or the like is used, and a p thin film is formed by an ion beam, an electron beam, or a sputtering method.

The protective layer has the same structure as the intermediate layer and is used to protect the recording layer from light, oxygen, moisture, scratches, dust, etc.

Next, a configuration example of the optical information recording medium of the present invention will be described with reference to the drawings.

FIG. 1 shows the basic structure of an optical information recording medium, in which a recording layer 2 containing a general formula dye is provided on a substrate 1. For recording and reproduction, laser beam 3 is recorded using a condensing lens.
The light is focused onto a spot with a size of 0.8 to 1.5 .mu.m on the surface of 2.

The laser beam 3 for recording and reproduction may be irradiated from the recording layer 2, but when the substrate 1 is made of a transparent material, the influence of dirt and dust can generally be reduced by irradiating it from the substrate 1 side.

FIG. 2 shows a structure in which an intermediate layer 4 is provided between the substrate 1 and the recording layer 2, and a protective layer 5 is provided on the recording layer 2.

In FIG. 3, two media having the same configuration are arranged with a spacer 6 in between so that the recording layers 2 face each other.

In addition, 7 in FIG. 3 is an air gap, and 8 is a spindle hole. According to such a configuration, the characteristics are good;
Furthermore, it has the advantage that the influence of dirt and dust on the recording layer 2 can be suppressed.

Furthermore, in the configurations of FIGS. 1 to 3 described above, AI-
+A reflective film such as Ag or other reflective film may be provided between the substrate and the recording layer.

[Embodiments of the invention]

Examples of the present invention will be described in detail below.

Example 1 The dye of structural formula a0 described above was dissolved in dichloromethane,
After forming a 2% solution, this solution was applied onto a glass substrate with a thickness of 1.2 μm using a spinner coater, and dried to form a recording layer with a thickness of 80 nm to obtain a recording medium.

When the reflectance of the recording layer of the obtained recording medium was measured with a spectrophotometer, it was 35% on the substrate side at a wavelength of 830 nm.
Met. Further, the output light of a semiconductor laser with a wavelength of 830 nm was focused onto the recording medium to a diameter of 1.2 μm, and an I MHz signal was written from the substrate side at a linear velocity of 6 m/see and an output power of mW. The recording sensitivity was 2.3 nJ/spot, and the reproduction CN value was 55 dB.

Example 2 The dye of structural formula (1) described above was dissolved in methyl ethyl ketone to make a 2% solution, and this solution was used as a base resin for an acrylic plate with a thickness of 1.2 wg that was base-treated with an ultraviolet curable resin. A recording layer having a thickness of 70 nm was formed by coating the film with a spinner coater and drying it, thereby obtaining a recording medium.

The reflectance of the recording layer of the obtained recording medium was at a wavelength of 830 nm.
m, it was 42% on the substrate side. Further, when writing and reproducing were performed on the recording medium using a semiconductor radar in the same manner as in Example 1, the recording sensitivity was 2. OnJ/Spot,
The reproduced CN value was 55 dB.

Example 3 After dissolving the dye of the above structural formula with methyl ethyl ketone to make a 2-chi solution, this solution was applied to a 1.2 m (7) 7-cryl plate with a base treatment of ultraviolet curable resin. A recording medium was obtained by coating the base resin with a spin f--r-coat and drying to form a recording layer with a thickness of 75 nm.

The reflectance of the recording layer of the obtained recording medium was at a wavelength of 830 nm.
In m, it was 39 inches on the substrate side. Further, when writing and reproducing were performed on the recording medium using a semiconductor laser in the same manner as in Example 1, the recording sensitivity was 2.1 nJ/spot,
The reproduced CN value was 53 dB.

Example 4 An acrylic resin (manufactured by Mitsubishi Rayon Co., Ltd., product name: Dianal B) as a binder resin was added to the dye of the above structural formula (b).
R-60) was added in an amount of 15% by weight, and this was dissolved in methyl ethyl ketone to make a 3-chi solution, and this solution was used as the base resin of a 1.2 tm thick acrylic plate that had been base-treated with an ultraviolet curable resin. It was coated on top using a spinner coater and dried to form a recording layer with a thickness of 90 nm to obtain a recording medium.

The reflectance of the recording layer of the obtained recording medium was at a wavelength of 830 nm.
There were 32 cases on the board side. Further, as in Example 1, υ writing and reproduction were performed on the recording medium using a semiconductor laser, and the recording sensitivity was 2.5 nJ/x pot and the reproduction CN value was 52 dB.

Example 5 The dye of structural formula (6) described above and an infrared absorber (product name: JRG-003, manufactured by Nippon Kaisha) were mixed at a weight ratio of 4:1, and this was dissolved in methyl ethyl ketone. After making a 3-layer solution, this solution was applied with a spinner coater onto the base resin of a 1.2 tone thick acrylic plate that had been base-treated with an ultraviolet curable resin, and dried to a thickness of 60 nm.
A recording medium was obtained by forming a recording layer of m.

The reflectance of the recording layer of the obtained recording medium is at a wavelength of 830 nm.
There were 42 cases on the board side. Also, when writing and reproducing was performed on the recording medium using a semiconductor laser in the same manner as in Example 1, the recording sensitivity was 20 nJ/7. Pot, the reproduction CN value was 55 dB.

Example 6 The dye of the above structural formula (6) and the dye of the following structural formula 07) were mixed at a weight ratio of 2:1, and this was mixed in Example 2.
It was dissolved in the same manner as above, coated on an acrylic plate with a thickness of 1.2 trm using a spinner coater, and dried to form a recording layer with a thickness of 80 nm to obtain a recording medium.

The reflectance of the recording layer of the obtained recording medium was at a wavelength of 830 nm.
In m, there were 41 cases on the board side. Further, when writing and reproducing were performed on the recording medium using a semiconductor laser in the same manner as in Example 1, the recording sensitivity was 1.8 nj/spot,
The reproduced CN value was 55 dB.

41-Example 7 The dye of structural formula (6) described above was coated on a glass substrate,
After drying to form a recording layer with a thickness of 60 nm, aluminum naphthalocyanine having the following structural formula (b) was deposited on the recording layer by vacuum heating under the condition of 1.0 x 10-5 torr. A reflective protective layer with a thickness of 20 nm was formed using the above steps to obtain a recording medium.

The reflectance of the recording layer of the obtained recording medium was at a wavelength of 830 nm.
In m, there were 43 cases on the board side. Further, when writing and reproducing were performed on the recording medium using a semiconductor laser in the same manner as in Example 1, the recording sensitivity was 2.1 nJ/spot,
The reproduced CN value was 52 dB.

Comparative Example 1 A dye having the following structural formula (1) was dissolved in methyl ethyl ketone to make a 2% solution, and this solution was treated as a base with an ultraviolet curable resin to form the base of an acrylic plate with a thickness of 1.2 tm. It was applied onto a resin using a spinner coater and dried to form a recording layer with a thickness of 80 nm to obtain a recording medium.

C6H13C6H13 The reflectance of the recording layer of the obtained recording medium is at a wavelength of 830 nm.
It was 35 mm on the substrate side. Further, when writing and reproducing were performed on the recording medium using a semiconductor laser in the same manner as in Example 1, the recording sensitivity was 2.8 nJ/spot,
The reproduced CN value was 52 dB.

Comparative Example 2 After dissolving the dye of the following structural formula (If) in dichloromethane to form a bimodal solution, this solution was applied onto the base resin of a 1.2 mm thick glass plate that had been base treated with an ultraviolet curable resin. coated with a spinner coater and dried to a thickness of 70 um.
A recording layer was formed to obtain a recording medium.

The reflectance of the recording layer of the obtained recording medium was at a wavelength of 830 nm.
It was 45 degrees on the substrate side at m. Further, when writing and reproducing were performed on the recording medium using a semiconductor laser in the same manner as in Example 1, the recording sensitivity was 3.1 nJ/szyt.
The reproduced CN value was 50 dB.

Comparative Example 3 After dissolving the dye with the following structural formula (B) in methyl ethyl ketone to make a 3-layer solution, this solution was placed on the base resin of a 1.2-thick acrylic plate that had been base-treated with an ultraviolet curable resin. Coated with a spinner coater and dried to a thickness of 70 nm
A recording medium was obtained by forming a recording layer of m.

The reflectance of the recording layer of the obtained recording medium is at a wavelength of 830 nm.
In m, the number was 39 on the board side. Further, when writing and reproducing were performed on the recording medium using a semiconductor laser in the same manner as in Example 1, the recording sensitivity was 2.2 nJ/spot,
The reproduced CN value was 54 dB.

Comparative Example 4 A dye having the following structural formula (IV) was dissolved in dichloromethane to make a 2% solution, and then this solution was applied onto the base resin of a 1.2 m thick glass plate that had been base treated with an ultraviolet curing resin. coated with a spinner coater and dried to a thickness of 70 nm.
A recording medium was obtained by forming a recording layer of m.

The reflectance of the recording layer of the obtained recording medium was at a wavelength of 830 nm.
30 on the substrate side. Further, when writing and reproducing were performed on the recording medium using a semiconductor laser in the same manner as in Example 1, the recording sensitivity was 3.1 nJ/sf and the reproduction CN value was 51 dB.

Furthermore, the recording media obtained in Examples 1 to 7 and Comparative Examples 1 to 4 were heated at 50° C. and at a relative humidity of 95% for 500 minutes.
Heat resistant
A moisture test was conducted. Mayu, 25℃, 60℃ for each recording medium.
% atmosphere, 500 W tungsten light was irradiated at 50 crn intervals for 100 hours, and a needle base test was conducted in which the reflectance reduction rate was similarly measured. Regarding playback deterioration of each recording medium,
As an accelerated test, the change in CN value was measured after continuous light with a laser output of 1 mW was irradiated for 30 minutes. The above results are shown in the table below.

〔Effect of the invention〕

As detailed above, the present invention has high reflectance and high recording sensitivity, enables stable writing and reproduction of optical signals, and has low stability against reproduction light, sunlight, and humidity. A highly pollution-free optical information recording medium can be provided.

[Brief explanation of drawings]

1 to 3 are schematic diagrams showing optical information recording media of the present invention, respectively. DESCRIPTION OF SYMBOLS 1... Substrate, 2... Recording layer, 3... Laser light, 4
... Intermediate layer, 5... Protective layer, 6... Spacer. Applicant's agent Patent attorney Atsushi Tsuboi Figure 2

Claims (1)

[Scope of Claims] An optical information recording medium characterized by having a recording layer containing an organic dye represented by the following general formula. ▲There are mathematical formulas, chemical formulas, tables, etc.▼ However, R_1 in the formula is an alkyl group with 1 to 6 carbon atoms, an allyl group, an aralkyl group, a phenyl group, and L is ▲There are mathematical formulas, chemical formulas, tables, etc.▼ [n =1~4
], ▲Mathematical formulas, chemical formulas, tables, etc.▼, ▲Mathematical formulas, chemical formulas,
There are tables, etc.▼, ▲There are mathematical formulas, chemical formulas, tables, etc.▼or▲There are mathematical formulas, chemical formulas, tables, etc.▼(Poly)methine chain group consisting of [W: indicates a monovalent group], X is Park anion selected from lolate, fluoroborate, iodide, chloride, bromide, and p-toluenesulfonate; Y is a functional group having 2 to 20 carbon atoms having an unsaturated bond; Z is a hydrogen atom, a halogen atom, and a carbon atom; Alkyl group of numbers 1 to 18, allyl group, nitro group, hydroxyl group, carboxyl group, alkoxyl group, -OCF_3, -OSF_
3, -R_2OH, -R_2COH, -R_2COOH
, -R_2OR_3, -R_2COR_3, -R2CO
OR_3, -COR_3, -COOR_3, ▲There are mathematical formulas, chemical formulas, tables, etc.▼, -CH=CH-CN, -NH
_2N(R_3)_2, -NHCOCH_3, ▲ Formula,
There are chemical formulas, tables, etc. ▼ (R_2: alkyl group with 1 to 20 carbon atoms, R_3: alkyl group with 1 to 18 carbon atoms) or a benzene ring added to the benzene ring constituting indole, m is 1 to 4 An integer of , denotes.